The present invention generally relates to vacuum waste systems and, more particularly, to a receptacle in a vacuum waste system having an automatically operable lid.
Vacuum waste systems are generally known in the art. Such systems typically comprise one or more waste receptacle, such as a toilet, in fluid communication with a waste tank. The waste tank is maintained at a pressure that is lower than that surrounding the toilet by a vacuum source, such as a vacuum pump or blower. In addition, when the vacuum waste system is provided on an aircraft, the lower tank pressure may be supplied by high altitude (i.e., above approximately 16,000 feet) atmospheric air. A flush valve, which opens in response to a flush command, is disposed between each toilet and the waste tank to control fluid communication between the toilet and the waste tank. The vacuum waste system may also include a spray ring for rinsing the toilet. The spray ring is connected by a rinse line to a source of rinse fluid. A rinse valve is disposed in the rinse line to control discharge of rinse fluid from the spray ring.
In operation, the rinse and flush valves are actuated in response to a flush command. The rinse valve is typically opened first to discharge rinse fluid from the spray ring, thereby to rinse the toilet. The flush valve is subsequently opened to establish fluid communication between the tank and the toilet outlet. The resulting pressure differential between the tank and the toilet forces waste material from the toilet to the tank. After a predetermined period has elapsed, the flush valve closes and the toilet is available for subsequent use.
While the flush valve is open, it will be appreciated that air from the toilet room is pulled into the vacuum waste system as long as a pressure differential exists. The incoming air may travel at a velocity sufficient to create noise that is audible outside of the toilet room. Such noise may be bothersome, particularly when the toilet room is located in close proximity to other people and is frequently used, such as on an aircraft.
Vacuum toilets are often provided with a lid that is movable between a generally vertical raised position and a generally horizontal lowered position. The lid, when placed in the lowered position, may significantly reduce the level of noise heard during a flush. A seal may be attached to the lid for closely conforming to the seat or toilet base, thereby to further reduce the noise level. For various reasons, however, the lid is rarely lowered before flushing. Some users are unaware or simply do not think to close the lid, while others find it inconvenient or unsanitary. Regardless of the reason, the lid is often left in the raised position during a flush cycle, thereby subjecting the area in the vicinity of the toilet to the maximum noise level.
In accordance with certain aspects of the present invention, a vacuum waste system adapted for use with a waste pipe maintained under partial vacuum pressure is provided. The vacuum waste system comprises a receptacle for receiving waste, the receptacle having an outlet in fluid communication with the waste pipe and an upper surface defining an opening. A flush valve is disposed in the waste pipe, the flush valve being normally closed but movable to an open position for a predetermined valve open period during a flush cycle. A lid is provided that is movable between a raised position, in which the lid is spaced from the opening defined by the upper surface, and a lowered position, in which the lid covers the opening. An actuator is operatively connected to the lid for holding the lid in the raised position, the actuator automatically driving the lid during the flush cycle to the lowered position before the flush valve is in the open position and returning the lid to the raised position after the predetermined valve open period, when the flush valve has returned to the closed position.
In accordance with additional aspects of the present invention, a vacuum toilet is provided for use with a waste pipe maintained under partial vacuum pressure. The vacuum toilet comprises a bowl having an upper surface defining an opening and a lid supported for pivotable movement between a lowered position, in which the lid covers the opening, and a raised position, in which the lid is rotated away from the opening. An actuator has a rod connected to the lid, the rod being movable between a first position, in which the lid is placed in the raised position, and a second position, in which the lid is placed in the lowered position. A controller is operatively connected to the actuator, wherein the controller normally operates the actuator with the rod in the first position, the controller automatically operating the actuator rod to the second position during a toilet flush cycle, and the controller automatically operating the actuator rod back to the first position after the toilet flush cycle.
In accordance with further aspects of the present invention, apparatus is provided for actuating a lid attached to a vacuum waste receptacle. The receptacle has an upper surface defining an opening, and the lid is movable between a lowered position, in which the lid covers the opening, and a raised position, in which the lid is spaced from the opening. The vacuum waste receptacle is adapted for selective communication with a waste pipe maintained under partial vacuum pressure. The apparatus comprises a pneumatic actuator having a cylinder and a rod operatively connected to the lid. The rod is movable between a first position, in which the lid is placed in the raised position, and a second position, in which the lid is placed in the lowered position. The cylinder is in fluid communication with the waste pipe for driving the rod between the first and second positions. A controller is operatively connected to the pneumatic actuator, wherein the controller normally operates the pneumatic actuator with the rod in the first position, automatically operates the actuator rod to the second position during a toilet flush cycle, and automatically operates the actuator rod back to the first position after the toilet flush cycle.